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51.
Z. A. Antonova V. S. Kruk V. N. Kursevich Yu. V. Maksimuk V. D. Sokolov 《Russian Journal of Applied Chemistry》2012,85(9):1447-1453
The results of calculations according to NRTL model of phase equilibrium of a binary system of THF-methanol and ternary system THF-methanol-water were demonstrated. 相似文献
52.
J. Ellrich R. Kruk R. A. Brand H. Hahn A. Hütten Y. Lei 《Hyperfine Interactions》2012,211(1-3):135-145
The purpose of this communication is to show that arrays of FePt with perpendicular anisotropy can be studied using energy-selective conversion electron M?ssbauer spectroscopy. Magnetic nanostructures have been in the focus of technology and science for many years. One of the economically and comparably scientifically most demanding application of these structures is in storage devices such as hard-disks and MRAMs. The FePt nanodisks presented here show a combination of material and magnetic properties which enable the fabrication of highly ordered nanostructures. 相似文献
53.
54.
A variety of ordered mesoporous carbons (OMCs) were synthesized using ordered mesoporous silicas (OMSs) as hard templates and the mesophase pitch (MP) as a carbon precursor. The synthesis included the mixing of OMS with MP, the infiltration of OMS with MP at 450–550?°C and the carbonization of MP in OMS/MP composite followed by the dissolution of the OMS template. OMCs with structures of two-dimensional hexagonal arrays of nanorods and three-dimensional arrays of nanospheres were obtained through the replication of silica templates, including large-pore SBA-15, KIT-6, large-pore FDU-12 and SBA-16. In particular, 2-D hexagonal array of carbon nanorods (CMK-3 carbon) with (100) interplanar spacing of ~13 nm as well as an array of carbon nanospheres arranged in the face-centered cubic structure with the unit-cell parameter of 33 nm were successfully prepared. The specific surface areas of the resulting carbons were up to 400 m2/g, and the total pore volumes were up to 0.43 cm3/g, with the highest values achieved when the MP infiltration temperature was 500?°C. The OMCs exhibited narrow mesopore size distributions. As inferred from XRD, the frameworks of OMCs featured semi-graphitic structures even though moderate carbonization temperature (850?°C) was employed. 相似文献
55.
W. Medycki J. Czaplicki D. Kruk C. Uniszkiewicz A. Mielczarek 《Applied magnetic resonance》2010,39(3):273-283
Dynamical properties of α-tocopherol acetate (commonly known as vitamin E) have been investigated in a broad temperature range
(below and above the glass transition) by means of proton spin–lattice relaxation. Two distinct relaxation processes have
been detected in the studied temperature range. One of them, present in the solid phase, has been attributed to reorientation
of methyl groups. In order to identify the motional process leading to the proton relaxation above the glass transition temperature
(T
g), molecular dynamics (MD) simulations have been performed, which provided time correlation functions for several internuclear
vectors in the molecule. The high-temperature relaxation process is primarily due to dynamics of the aromatic rings of the
tocopherol molecule; however, a considerable contribution of diffusion of the aliphatic chain cannot be excluded. Comparing
the nuclear magnetic resonance (NMR) results with MD and relaxation data of dielectric spectroscopy (DS) available in the
literature (K. Kamiński, S. Maślanka, J. Zioło, M. Paluch, K.J. McGrath, C.M. Roland, Phys Rev E 75:011903-7, 2007; E. Szwajczak, J. Świergiel, R. Stagraczyński, J. Jadżyn, Phys Chem Liq 47:460–466, 2009), the motional process observed in NMR relaxation studies above T
g has been identified with the δ process observed in DS. 相似文献
56.
Rajadurai C Schramm F Brink S Fuhr O Ghafari M Kruk R Ruben M 《Inorganic chemistry》2006,45(25):10019-10021
A one-dimensional supramolecular head-to-tail N+ -H...N-type hydrogen-bonded chain of the complex [FeII(L)2H](ClO4)3.MeOH [L = 4'-(4'-pyridyl)-1,2':6'1'-bis(pyrazolyl)pyridine] exhibits a reversible, thermally driven spin transition at 286 K with a hysteresis loop of ca. 2 K. 相似文献
57.
The aim of this paper was to determine the extent of contamination by anthropogeneous radionuclides 137Cs and 90Sr in the bottom sediments from the Barents Sea based on the radioactive activity of the samples taken up in August 1991,
among others, from the area close to New Land Island and Francis Joseph Archipelago. The results are based on the phenomenon
of vertical migration, in the bottom sediments which is of significant importance from the natural environment point of view. 相似文献
58.
The current work demonstrates that the standard adsorption analysis has a limited applicability for characterization of chemically modified porous silicas. Since low-pressure nitrogen adsorption isotherms are sensitive to the surface changes caused by chemical modification of silicas, these isotherms were successfully used to evaluate their surface heterogeneity during different stages of modification. The surface analysis was accomplished by using adsorption energy distributions and high-resolution comparative plots. 相似文献
59.
60.
Danuta Kruk Elzbieta Masiewicz Evrim Umut Martin Schlögl Roland Fischer Hermann Scharfetter 《Molecular physics》2019,117(7-8):944-951
ABSTRACT1H spin-lattice relaxation studies have been performed for pure [Bi(NO3)3(H2O)3]*18-crown-6 in powder and its solution in dimethyl sulfoxide (DMSO). The experiments have been carried out in the frequency range of 10?kHz–30?MHz and the temperature range of 240–277?K; at 277?K the solution is already frozen. The 1H relaxation of pure [Bi(NO3)3(H2O)3]*18-crown-6 has been interpreted in terms of three dynamical processes. Quadrupole Relaxation Enhancement effects have been observed in the frozen DMSO solution of [Bi(NO3)3(H2O)3]*18-crown-6. The specific mechanisms of the 1H spin-lattice relaxation enhancement have been discussed distinguishing between effects caused by time independent (residual) and fluctuating 1H-209Bi dipole-dipole interactions. 相似文献